<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
         .nav{
            width: 100%;
            height: 50px;
            line-height: 50px;
            background-color: rgb(143, 142, 153);
         }
         .nav ul{
            list-style: none;
            display: flex;
            justify-content: center;
            align-items: center;
         }
         .nav ul li{
            margin: 0 10px;
         }
         .nav ul li a:hover{
            color: #fff;
            text-decoration: none;
            background-color: rgb(143, 142, 153);
            /* 除去下划线 */
            text-decoration: none;
         }
         .nav ul li a{
            /* 除去下划线 */
            text-decoration: none;
         }

    </style>
</head>
<body>
    <div class="nav">
        <ul>
            <li class="box1"><a href="#">首页</a></li>
            <li class="box2"><a href="#">电视</a></li>
            <li class="box3"><a href="#">音频</a></li>
            <li class="box4"><a href="#">视频</a></li>
            <li class="box5"><a href="#">联系我们</a></li>
        </ul>
    </div>
</body>
</html>